The 2005 USC Trojans football team represented the University of Southern California in the 2005 NCAA Division I-A football season, winning the Pacific-10 Conference (Pac-10), and playing for the NCAA Division I-A national championship. The team was coached by Pete Carroll, led on offense by quarterback and 2004 Heisman Trophy winner Matt Leinart, and played their home games in the Los Angeles Coliseum.

The 2005 NCAA Division I-A football season was the highest level of college football competition in the United States organized by the National Collegiate Athletic Association (NCAA). The regular season began on September 1, 2005 and ended on December 3, 2005. The postseason concluded on January 4, 2006 with the Rose Bowl, which served as the season's BCS National Championship Game.